The invention generally relates to auxiliary vehicle heater for providing heat to the interior of the vehicle when the motor is not operating and more specifically to an auxiliary truck heater which utilizes vehicle fuel and heats the motor coolant so that heat may be extracted therefrom in the heater core of the vehicle's heater.
Large, long haul trucks present cabin heating difficulties. Although they are routinely equipped with cab heaters having heater cores through which the motor coolant circulates, this configuration addresses the issue of cabin heat only when the vehicle's motor is operating. The answers to two following questions quickly define the problem. The first question is: is cabin heat required when the vehicle is not moving. Very frequently, the answer is yes. The second question is: is the operation of the vehicle engine by any standard an efficient way to heat the cabin. The answer to this question is a uniform and acknowledged no.
In view of the foregoing, numerous products have been designed to address the need for auxiliary heat in motor vehicle cabs which do not require operation of the vehicle motor. Patents addressing such products are also known.
For example, U.S. Pat. No. 4,192,457 discloses an early auxiliary truck heater intended primarily to heat the vehicle engine and fuel line when the engine is not operating. In U.S. Pat. No. 4,718,602 an auxiliary vehicle heater is disclosed which includes a subassembly including a nozzle hose, a fuel pump, a filter and a solenoid valve. U.S. Pat. Nos. 5,046,663 and 5,082,175 also present various embodiments of auxiliary truck heaters.
Within the last several years, software available in programmable microprocessors has improved both the operation and safety of such devices. U.S. Pat. No. 5,063,513 discloses such a heater and control device wherein the controller may be programmed to commence operation at a preselected time in order to warm the vehicle passenger compartment appropriately and efficiently.
In review of these and other patents reveal the complexity of such devices and suggests that improvements in the art of auxiliary vehicle heaters are both possible and desirable.